Lota-beam



H. A. 'FABER Jan. 3, 1939.

I' BEAM Original Filed Sept. 1, 1936 CTL Patented Jan. 3, 1939 UNI-TED STATES PATENT OFFICE Application September 1, 1936, Serial No. 98,890 Renewed May 28, 1938 1 claim.

This invention relates to a. structural unit, and more particularly to a structural unit assembled from metal or equivalent material elements expanded to desired cooperating formation.

Pursuant to the invention beams, girders, and other structural unitsof the nature of an I-beam may be easily and inexpensively assembled from ordinary stock sizes of material, preferably structural steel, to embody the combined characteristics of strength and lightness.

The m-ethod preferably employed to produce the individual expanded elements, consists, broadly, in slitting stiff sheet material, usually metal, plurally, diagonally to its length, the slits extending substantially parallel to one another and, collectively, substantial-1y parallel with such length, and expanding such material across its width to form lengthwise-members integrally connected by a plurality of spaced, substantially mutually parallel cross-members.

I-beams pursuant to this invention may be used, generally, in building construction, and especially as floor joists in such constructions.

In fabricating the I-beam, channel-irons of any suitable material and configuration are prepared in the aforesaid manner, i. e. by making a plurality of slits across the width of the web thereof, diagonally to the width and the length thereof; thereafter each channel-iron is expanded across its Width by subjecting the web to mutually opposing outwardly directed forces acting in the plane of the slits, and at an angle other than 180 to the length of the slits.

Expansion of the channel-irons continues only to an extent suflicient to direct the resulting cross-members diagonally, in the desired degree, with respect to the length and width of the resulting expanded element. The expanded channel-irons are thereafter rigidly secured to each other with their respective web outer faces contiguous and substantially coextensive one with the other.

To afford high load-bearing characteristics and great rigidity for the resulting beam, the expanded channel-iron elements are associated in the described manner so that the collective slants of the cross-members of one channel element is oppositely directed to the collective slants of the cross-members of the other channel element, and stands so that each cross-member of one channel element forms, geometrically, the diagonal of one of the parallelograms formed by two mutually adjacent cross-members of the other channel element.

In the drawing which illustrates only one embodiment of the present invention,

Fig. 1 is a perspective view of a channel-iron slitted according to a preliminary stage of the present method.

Fig. 2 is a view corresponding to that of Fig. 1,

but representing the channel-iron in an advanced stage of expansion.

Fig. 3 represents a side elevation of an I-beam completely assembled pursuant to the present invention.

Fig. 4 represents a vertical section taken on the line 4--4, Fig. 3, and slightly enlarged.

Fig. 5 represents a side elevation of a fragment of the I-beam of Fig. 3, illustrating one method of rigidly securing the expanded channel-iron elements to each other.

Fig. 6 is a View corresponding to Fig. 5, but illustrating another method of rigidly securing the expanded channel-iron elements to each other.

Fig. 7 represents a horizontal section taken on the line '1 -1, Fig. 6.

Referring to the drawing, an embodiment of this invention, completely assembled pursuant to the present method, is illustrated in Fig. 3 in the form of an I-beam for use as a structural unit in building construction.

As directed specifically to the fabricating of the I-beam, illustrated in Fig. 3, the method comprises cutting a plurality of slits across the width of the web Illa of a standard stock size, or other type, channel-iron l0, refer to Fig. 1, diagonally to the width and the length thereof, the stated slits being indicated respectively at l l.

As a further step, the web ia of the channeliron I is expanded across its width by subjecting it to mutually opposing outwardly directed forces acting in the plane of the slits and at an angle other than 180 to the length of the slits, and preferably acting normal to the length of the flanges 10b of the channel-iron I0. The forces may be conveniently applied directly to the flanges |0b in effecting the `expansion of the web. The expansion is continued only to an extent suflicient to direct the resulting cross-members, indicated respectively at I2, Fig. 2, diagonally in the desired degree with respect to the resulting lengthwise-members I3a and 13b respectively. Advantageously, the ends cf the completely expanded elements are squared, as indicated by the dotted lines ca -a, and b-b, Fig. 2, to provide elements coextensive in dimensions, and adapted to cooperate with each other, in the fabrication of the I-beam.

As a final step, two of the prepared expanded channel-iron elements are associated, and preferably rigidly secured together, with the web outer face, see lUc, Fig. 2, of respective elements contiguous and substantially coextensive one With the other, as illustrated in Fig. 3. As illustrated, the respective channel-iron elements are so associated that the cross-members l2 of one element are collectively oppositelyl directed to the collective cross-members I2 of the other element, and each cross-member of one channel element forms, geometrically, the diagonal of one of the parallelograms formed by two mutually adjacent cross-members of the other channel element. Intimate association of the two elements in the prescribed manner allord high loadbearing characteristics and great rigidity for the resulting I-beam. The voids i4, produced, in the expansion of the elements, between adjacent cross-members I2, and between lengthwise-members I3a. and |3b, make for lightness of the completely fabricated unit.

The channel-iron elements I0, associated as illustrated in Fig. 3, may be rigidly s-ecured to each other in any suitable manner, as for instance by rivets l5, Fig. 5, supplied at spaced intervals along the lengthwise-members |3a and |31). Advantageously, a plurality of tongues I6, Fig. 7, are blanked out of the material of the web Illa, at the margins of same, during the operation of cutting the slits Il. Such tongues I6 are provided at spaced intervals along the length of the margins of the web, and, in assembling the expanded elements, are adapted to cooperate in the manner illustrated in Fig. 7, to rigidly secure the elements to each other.

To give added rigidity to the expanded elements, and to enhance the load supporting characteristics of the I-beam herein described, the lateral edges of the cross-members may be bent, preferably at right angles to the body of the cross-member, to provide lateral flanges (not illustrated) therefor; or any form of crimping, suitable for the purpose, may be employed. It is preferred to accomplish such bending or crimping during, and desirably as a part of, the cutting and stamping operation.

Whereas this invention has been described with kreference to particular forms thereof, it is to be distinctly understood that many changes may be made therein, without departing from the spirit of the invention as dened in the claim following this specification.

I claim:

A structural I-beam comprising two similarly congurated expanded-metal channel elements rigidly secured to each other with their web outer faces contiguous and substantially coextensive one with the other, each of said channel elements comprising spaced mutually parallel flanges integrally connected by a series of mutually parallel cross-members diagonally disposed with respect to the flanges, the two channel elements being so related to each other that the collective slants of the cross-members of one channel element is oppositely directed to the collective slants of the cross-members of the other channel element, and each cross-member of one channel element forms, geometrically, the diagonal of one of the parallelograms formed by two mutually adjacent cross-members of the other channel element.

HERBERT ALFRED FABER. 

